As a packaging material for packaging various articles such as food, medicine, medical products and miscellaneous goods, a packaging bag provided with a zipper tape have been used, in which a pair of belt-like zipper tapes respectively including a male member and a female member that are mated with each other is disposed on an opening of the bag, the zipper tapes capable of being opened from the mated state and closable again.
Such a packaging bag provided with a zipper tape is sealed at an upper side of the zipper tape. When the packaging bag is to be opened, a film forming a bag body are torn apart starting from notches and the like provided on either side of the packaging bag.
When the packaging bag is to be thus opened, the film of the packaging bag is cut closely along the zipper tape to cause difficulty in pinching the bag body. Accordingly, a technique has been demanded that allows the film of the bag body to be cut at a predetermined position.
For instance, as disclosed in Patent Literature 1, such an arrangement that a packaging bag can easily be cut at a predetermined position has been known.
In the packaging bag disclosed in Patent Literature 1, a belt-like base of a male member of a zipper tape attached to an inner surface of a bag body includes: a main body on which an engagement portion is provided; a first projecting portion provided to the main body near an opening of the packaging bag; a thin portion provided to the first projecting portion near the opening; and a second projecting portion provided to the thin portion near the opening. A belt-like base of a female member includes: a main body; a first projecting portion; a thin portion; and a second projecting portion. When the zipper tape is fused onto the bag body, a gap is formed between the thin portions and a film of the bag body.
Since the first and second projecting portions provided across the thin portion are produced thicker than the thin portion, even when a cutting line goes out of the thin portion, the thick first and second projecting portions are not cut. Accordingly, level differences are produced between the thin portion and the first projecting portion and between the thin portion and the second projecting portion, so that the thin portion is easily cut along the level differences.